Close dashboard auth boundary follow-up

[Jurij89]

Summary

• Closes Follow up PR #1428 dashboard auth boundaries and session test organization #1433 by making the daemon dashboard auth context an explicit lifecycle-to-route/SSE handoff instead of relying only on the legacy request-symbol side channel.
• Centralizes dashboard auth-source backing-token validation in resolveRequestAuthDecision() before the dashboard source builds an accepted request context.
• Adds RequestContext.requestIdentity as the canonical route identity while preserving requestAuth, requestToken, and requestAgentAddress compatibility aliases.
• Splits the dashboard session monolith into focused route, login, auth-source, cookie, store, and route-identity suites with a shared HTTP harness.

Files Changed

• packages/cli/src/auth.ts
• packages/cli/src/daemon/dashboard-session-auth-source.ts
• packages/cli/src/daemon/dashboard-sse-session.ts
• packages/cli/src/daemon/handle-request.ts
• packages/cli/src/daemon/lifecycle.ts
• packages/cli/src/daemon/route-request-identity.ts
• packages/cli/src/daemon/routes/context.ts
• packages/cli/test/dashboard-*.test.ts
• packages/cli/test/route-request-identity-dashboard.test.ts
• packages/cli/test/dashboard-session-test-harness.ts
• packages/cli/vitest.unit.config.ts

Verification

• pnpm install --frozen-lockfile
• pnpm run build:runtime:packages
• cd packages/cli && pnpm exec vitest run test/auth.test.ts test/dashboard-login.test.ts test/dashboard-session-auth-source.test.ts test/dashboard-session-cookie.test.ts test/dashboard-session-store.test.ts test/dashboard-session.test.ts test/route-request-identity-dashboard.test.ts --config vitest.unit.config.ts - 116 tests passed
• cd packages/node-ui && pnpm exec vitest run test/app-primer-route.test.ts test/dashboard-session-gate.test.ts test/dashboard-session-client.test.ts --reporter=dot - 12 tests passed
• cd packages/cli && pnpm exec tsc --noEmit --pretty false
• git diff --check

Broader Unit Note

I also ran cd packages/cli && timeout 8m pnpm exec vitest run --config vitest.unit.config.ts. It completed with unrelated local-environment failures on this WSL host:

• real-daemon suites could not find /tmp/dkg-hardhat-ctx-9545.json because the Hardhat shared context was not running;
• MCP setup assertions were polluted by real Windows-side client config detection in this WSL environment.

The touched dashboard/auth suites passed in that broader run.